Coupling agent compositions

ABSTRACT

Coupling agent and primer compositions comprising a conventional silane coupling agent (1), and a disilyl crosslinker compound (II) of the general formula 
     
         (RO).sub.3 SiR&#39;Si(OR).sub.3 
    
     where RO denotes a hydrolyzable group, R&#39; denotes a divalent organic radical, and the weight ratio of (I) to (II) is between 1:99 and 99:1 inclusive.

.Iadd.

This is a reissue of Ser. No. 06/880,528; U.S. Pat. No. 4,689,085..Iaddend.

BACKGROUND OF THE INVENTION

This invention relates to coupling agent compositions comprising aconventional silane coupling agent and a bis(trialkoxysilyl)organocompound, and partially hydrolyzed products of such mixtures. Thesecoupling agent compositions can also be used as primers in theproduction of laminates and other composite materials.

Conventional silane coupling agents are well known in the plasticforming and composite materials arts for bonding resins to fillers andsubstrates. Typically as part of the process of producing compositematerials, reinforcing fillers are treated with silane coupling agentsbefore being introduced into the uncured resin. The silane couplingagents form a coating on the filler, and the coating interacts with theresin, either chemically or through the formation of interpenetratingpolymer networks, to form a strong cohesive bond between the resin andfiller. A significant benefit of silane coupling agents is the addedhydrolytic stability they provide composite materials.

The particular silane coupling agent which will produce the strongestand most hydrolytically stable composite material depends upon the resinused in said composite. Ordinarily, the silane coupling agent is chosenbased upon the functionality of the nonhydrolyzable group attached tothe silane, however, some silanes are effective coupling agents withresins even where the silane is relatively unreactive with the resinused in the composite. Recommendations for choosing the most effectivecoupling agent for a particular filler/resin combination are present inthe art.

The performance and cost of silane coupling agents, while adequate, canbe improved by the addition of further chemical compounds. U.S. Pat. No.3,816,152, issued to P. C. Yates Jun. 11, 1974, teaches the addition ofsilicic and polysilicic acid to organofunctional silanes to lower thecost of coupling agent compositions. While these compositions areeffective coupling agents, they do not in all cases provide compositesas strong as composites made with organofunctional silane couplingagents alone. Thus, a coupling agent composition more effective than theorganofunctional silane alone would be useful in the plastic formingarts.

GENERAL DESCRIPTION

This invention relates to coupling agent and primer compositionscomprising a conventional silane coupling agent (I), and a disilylcrosslinker compound (II) of the general formula

    (RO).sub.3 SiR'Si(OR).sub.3

where RO independently denotes a hydrolyzable group, R' denotes adivalent organic radical, and the weight ratio of the silane couplingagent to the disilyl crosslinker compound is between 1:99 and 99:1inclusive. The compositions may further include a mutual solvent of thesilane coupling agent and the disilyl crosslinker compound.

The compositions of the present invention are effective as both couplingagents and as primers. The compositions of the present invention can beused in a wide range of polymer composite materials including filledsystems, laminates, and coatings. The compositions can be used as primercoats between nonparticulate surfaces and polymer coatings, aspretreatments for particulate fillers before compounding, and asadditives to filled polymer systems during compounding. The compositionscan also be used to treat glass cloth used in laminates.

DETAILED DESCRIPTION OF THE INVENTION

This invention relates to coupling agent and primer compositionscomprising a conventional silane coupling agent (I), and a disilylcrosslinker compound (II) of the general formula

    (RO).sub.3 SiR'Si(OR).sub.3                                (i)

where RO denotes an alkoxy radical with 1 to 8 carbon atoms, or someother hydrolyzable radical such as an alkoxyalkoxy radical or an acetoxyradical, R' denotes a divalent organic radical which is less than 15bond lengths between the two silyl groups, and the weight ratio of thesilane coupling agent to the disilyl crosslinker compound is between1:99 and 99:1 inclusive. The compositions may further include a mutualsolvent of the silane coupling agent and the disilyl crosslinkercompound.

Also within the scope of the present invention are partially hydrolyzedmixtures and solutions of silane coupling agents and disilyl crosslinkercompounds. For instance, a mixture of 10 grams of a silane couplingagent, 10 grams of a disilyl crosslinker, 75 grams of a mutual solventand 5 grams of water would be within the scope of the present invention.The silane coupling agent and the disilyl crosslinker compound would bepartially cohydrolyzed in such a solution.

Various conventional silane coupling agents (I) can be used inconjunction with the the crosslinkers of the present application.Generally, silane coupling agents are of the formula

    A.sub.(4-n)SiY.sub.n

where A is a monovalent organic radical, Y is a hydrolyzable radical,and n is 1, 2, or 3 (most preferably 3). A can be various types oforganic radicals including alkyl or aryl radicals and various functionalradicals such as methacryloxy, methacryl, epoxy, chloroalkyl, carboxyl,vinyl or allyl, styryl, amino, diamino, azo, and azido radicals. Yradicals hydrolyze in the presence of water and include acetoxyradicals, alkoxy radicals with 1 to 6 carbon atoms, alkoxyalkoxyradicals with 2 to 8 carbon atoms, and chloro radicals.

Specific silane coupling agents within the scope of the claimedcompositions include N-(2-aminoethyl)-3-aminopropyltrimethoxysilane,3-methacryloxypropyltrimethoxysilane, 3[2(vinylbenzyiamino)ethylamino]propyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane,triacetoxyvinylsilane, tris-(2-methoxyethoxy)vinylsilane,3-chloropropyltrimethoxysilane,1-trimethoxysilyl-2-(p,m-chloromethyl)phenyl-ethane,3-chloropropyltriethoxysilane,N-(aminoethylaminomethyl)phenyltrimethoxysilane,N-(2-aminoethyl)-3-aminopropyl tris(2-ethylhexoxy)silane,3-aminopropyltrimethoxysilane, trimethoxysilylpropyldiethylenetriamine,beta (3,4-epoxycyclohexyl)ethyltrimethoxysilane,3-mercaptopropyltrimethoxysilane, 3-mercaptotriethoxysilane,3-mercaptopropylmethyldimethoxysilane,bis(2-hydroxyethyl)-3-aminopropyltrimethoxysilane. 1,3divinyltetramethyidisilazane, vinyltrimethoxysilane,2-(diphenylphosphino)ethyltriethoxysilane,2-methacryloxyethyldimethyl[3-trimethoxysilylpropyl)ammonium chloride,3-isocyanatopropyldimethylethoxysilane,N-(3-acryloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane, vinyltris(t-butylperoxy)silane, 4-aminobutyltriethoxysilane,methyltrimethoxysilane, ethyltrimethoxysilane, phenyltrimethoxysilane,and phenyltriacetoxysilane.

Other silane compounds which are considered silane coupling agents forthe purpose of the present application include methyltrimethoxysilane,phenyltrimethoxysilane, ethylorthosilicate, phenyltriethoxysilane andn-propylorthosilicate.

Azide functional silanes, of the general formula

    Y.sub.3 SiR'"SO.sub.2 N.sub.3

where Y denotes a hydrolyzable group such as an alkoxy, an alkylalkoxyor a chloro radical, and R'" denotes a divalent organic radical, arealso within the scope of the invention .Iadd.and .Iaddend.can also beused.

The most preferred silane coupling agents are those which arecommercially available and which are recognized by those skilled in theart as being effective coupling agents. In particular, the mostpreferred silane coupling agents includeN-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3[2(vinylbenzylamino)ethylamino]propyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane,3-glycidoxypropyltrimethoxysilane, triacetoxyvinylsilane,tris-(2-methoxyethoxy)vinyisilane, 3-chloropropyltrimethoxysilane,3-aminopropyltrimethoxysilane, vinyltrimethoxysilane,mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane and theazide functional silanes of the formula .[.X₃ Sir'"SO₂ N₃,.]. .Iadd.X₃SiR'"SO(₂ N₃ .Iaddend.where X denotes a hydrolyzable group such as analkoxy, an alkylalkoxy or a chloro radical, and R'" denotes a divalentorganic radical.

The most preferred silane coupling agents are commercially available.The other silane coupling agents are available commercially, or theirpreparation is known in the art.

The disilyl crosslinker compounds (II) of the present invention arerepresented by formula (i), wherein RO denotes a hydrolyzable radical,and R' denotes a divalent organic radical. For the purposes of thisapplication, divalent organic radicals is deemed to include divalentorganosilicon radicals. Within the scope of the present invention R' canvary and includes alkylene radicals with 1 to 8 carbon atoms, ordivalent radicals of the following formulae ##STR1## where x and y are 1to 5, ##STR2## where s, t, u, and v are 1 to 3 inclusive.

Particular divalent organic radicals include, but are not limited to,divalent radicals of the .[.follow.]. .Iadd.following .Iaddend.formulae##STR3##

The R' radical can also be methylene, ethylene, propylene, hexylene, andmeta or para phenylene radicals.

It is important in the practice of the invention that the divalentorganic radical not be bulky. There should be less than 15 bond lengthsin the chain linking the silyl radicals. The most preferred radicalshave less than 10 bond lengths between the silyl radicals.

The most preferred R' radicals are methylene, ethylene, meta- or para-phenylene and the trans isomer of formula .[.d.]. .Iadd.c.Iaddend.above.

RO denotes hydrolyzable radicals such as alkoxy radicals with one toeight carbon atoms, alkoxyalkoxy radicals with two to ten carbon atoms,a hydroxy radical, or an acetoxy radical.

The syntheses of the disilyl crosslinker compounds are known in the art.The disilylalkyl compounds can be synthesized by reactingcholoralkytrialkoxysilane with tetraalkoxysilane (represented by theformula SiX₄ where X is an alkoxy group) in the presence of lithium.

The bis(trimethoxysilyl)benzene compounds can be synthesized by reducingbis(trichlorosilyl)benzene with lithium aluminum halide followed bymethanolysis as described in Preparation and Characterization ofDisilylbenzene and Bis(trimethoxysilyl)benzene, Bilow, et al., J. Org.Chem. 26(3) 929, 1961.

The disilyl crosslinker compounds corresponding to formula (d) above canbe synthesized by any of the means taught in U.S. Pat. No. 3,179,612,especially by the method taught in Example 2 of said patent.

The disilyl crosslinker compounds corresponding to formula (c) can besynthesized by reacting polyamines with chloroalkylsilanes according tothe method taught in U.S. Pat. No. 4,448,694.

The coupling agent compositions of the present invention can be used ascoupling agents in a wide variety of composite materials. A wide rangeof fillers and resins can be used in these composites. It is thoughtthat the present compositions can be used with any combination of fillerand resin, if the appropriate conventional silane coupling agent is usedin the composition. The art provides useful references teaching specificsilane coupling agents for use in a particular resin/filler compositecombination. For instance, Petrarch Systems, Inc. Silicon CompoundsRegister and Review, Petrarch Systems, Inc., Bristol, Pa. 19007, 1985provides a useful guide in choosing silanes for particular resins, asdoes A Guide to Dow Corning Silane Coupling Agents, Dow CorningCorporation, Midland, Mich. 48640, 1985.

Fillers, both particulate and fibrous, which could be used in compositesemploying the coupling agent compositions of the present inventioninclude siliceous materials such as glass, quartz, ceramic, asbestos,silicone resin and glass fibers, metals such as aluminum, steel, copper,nickel, magnesium, and titanium, metal oxides such as MgO, Fe₂ O₃, andAl₂ O₃, and metal fibers and metal coated glass fibers.

The ratio of silane coupling agent to disilyl crosslinker can varywidely. The weight ratio of silane to disilyl crosslinker can vary from1:99 to 99: 1, inclusive, although their ratio is preferably within therange of about 1:9 to 9:1. The most preferable weight ratios forpolyester glass laminates is about 2:9 to 1:9.

The silane coupling compositions of the present invention can furthercomprise a solvent capable of solubilizing both the conventional silanecoupling agent and the disilyl crosslinker compound. Typically suchsolvents include lower alcohols such as methanol, butanol orisopropanol. Water can also be used as a solvent, but the stability ofsuch solutions is much more limited than the solutions made withalcohols. Small portions of water can be added to the coupling agentsolutions in order to hydrolyze the conventional silane coupling agentand the disilyl crosslinker.

The solids contents of the coupling agent compositions of the presentinvention varies from 100 weight percent in pure mixtures to as littleas 0.1 weight percent or less in very dilute solids solutions.

The following examples demonstrate particular embodiments of the presentinvention. Some of the examples are comparative examples offered todemonstrate the effectiveness of the present invention relative to theprior art. The examples do not delineate the full scope of theinvention.

EXAMPLE 1

This example demonstrates the effectiveness of the present invention inadhering polymeric materials to metal. Cold rolled steel and titaniumsurfaces were primed with a 10 weight percent isopropanol solution of aconventional silane coupling agent, 3-methacryloxypropyltrimethoxysilane(A). Steel and titanium surfaces were also primed with a 10 weightpercent solution of a mixture of I weight parthexamethoxy-1,2-disilylethane and 10 weight parts of3-methacryloxypropyltrimethoxysilane (B). Commercially available,crosslinkable polyethylene vinylacetate terpolymer was adhered tounprimed steel and titanium surfaces and to the primed steel andtitanium surfaces by applying the polymer under low pressure at 130° C.Upon cooling to room temperature, the adhesion of the polymer to themetal surface was determined by measuring the force applied 90 degreesto the metal surface required to peel the polymer film from the metal.Adhesion of the polymer to the metal was also measured after the sampleshad been immersed in water at 80° C. for 2 hours and cooled to roomtemperature. The results are reported in Table 1.

                  TABLE 1                                                         ______________________________________                                        Peel/Strength (lbs./inch)                                                            Titanium          C.R. Steel                                           Primer   Initial Immersed    Initial                                                                             Immersed                                   ______________________________________                                        None     Nil     Nil         Nil   Nil                                        A        c       0.15        c     4.0                                        B        c       6.15        c     c                                          ______________________________________                                         Note: c denotes cohesive failure of the polymer at greater than 16            lb./inch.                                                                

The results show the increased effectiveness of the present invention inadhering polyethylene copolymers to primed metal surfaces versusconventional silane coupling agents. Primer B, an embodiment of thepresent invention, more effectively adhered ethylene vinylacetateterpolymer to titanium than the prior art coupling agent A, bothinitially and after immersion in 80° C. water for 2 hours. Primer Bimproved the adhesion of the polymer to cold rolled steel to the extentthat even after water immersion the cause of failure of the compositewas cohesive failure of the polymer film rather than failure of the bondbetween the film and the metal surface.

EXAMPLE 2

This example illustrates the effectiveness of the invention in adheringvarious polymers to glass slides. 10 weight percent solids, methanolsolutions encompassed within the present invention were made by diluting9 weight parts of3[2(vinylbenzylamino)-ethylamino]propyltrimethoxysilane coupling agentwith 1 weight part of one of the disilyl crosslinker compounds listedbelow: ##STR4## Comparative example primers were made with mixturescomprising 9 weight parts3[2(vinylbenzylamino)ethylamino]propyltrimethoxysilane, and I weightpart of one of the following silane crosslinkers:

    C.sub.6 H.sub.5 Si(OCH.sub.3).sub.3                        9.

    Si(OCH.sub.2 CH.sub.3).sub.4,                              10. diluted to 10 weight percent solids in methanol. The primers were partially hydrolyzed by adding 5 weight percent water to the solutions. Glass microscope slides were coated with the primers and dried. Three types of polymers were applied to the primed surfaces and the 90 degree peel strength of the polymer films was measured after immersing the sample in water. The three polymers used were a crosslinkable ethylene vinylacetate copolymer resin (C-EVA) sold be Springborn Laboratories of Enfield, Conn. as EMA™15295; a thermoplastic ethylene vinylacetate terpolymer (EVA) sold by E. I. du Pont de Nemours & Company, Inc., Wilmington, DE, as CXA-2022™; and a styrene-butadiene block copolymer (SB) sold by Shell as Kraton™ 1102. The crosslinked ethylene vinylacetate (C-EVA) samples were immersed in water at 70° C. for 2 hours. The EVA samples were immersed in 70° C. for 1 and 4 hours before being measured. The SB polymer was immersed in 100° C. water for 6 hours. The results are reported in Table 2.

                  TABLE 2                                                         ______________________________________                                        (Peel/Strength (lb./inch)                                                     Polymer                                                                       Primer           EVA                                                          Additive                                                                             C-EVA     1 Hour  4 Hours [CB]SB                                       ______________________________________                                        None*  0.4       7.0     0.4     nil                                          1      6.6       13.6    1.8     11.0                                         2      3.5       9.9     0.7     7.7                                          3      2.6       5.0     0.7     0.3                                          4      8.8       9.0     1.3     >18.0                                        5      4.0       4.8     1.1     11.0                                         6      1.1       2.6     nil     0.2                                          7      7.5       >18.0   7.0     >18.0                                        8      1.1       6.4     1.3     0.7                                           9*    4.6       9.5     0.7     0.3                                          10*    4.6       2.6     1.0     6.2                                          ______________________________________                                         *The primer was a 10 weight percent solids solution of partially              hydrolyzed 3[2(vinylbenzylamino)ethylamino]propyltrimethoxysilane with no     crosslinker additive.                                                    

The results demonstrate that mixtures of partially hydrloxyzed silanecoupling agents with disilyl crosslinkers are effective primers. All ofthe mixtures within the scope of the invention showed improved adhesionbetween glass slides and at least one of the three polymer systems.Primers 1, 4, and 7 showed across the board improved adhesion relativeto the adhesion promoters known in the art (comparative primers 9 and10). Primers 2 and 5 showed improved adhesion with certain polymers overthe prior art.

EXAMPLE3

This example demonstrates the effectiveness of the present invention asa coupling agent in Novacite filled polyester resin castings. 40 weightpercent methanol solutions of mixtures comprised of 10 weight partsconventional silane coupling agent and 1 weight part of the crosslinkingagents of Example 2 were made. Fifty parts of Novacite™, a naturalmicroform of low quartz, (DAPER™- Malvern Minerals) was mixed with 50parts of a polyester resin sold as Co Resyn™ 5500 by Interplastic Corp.,Minneapolis, Minn., and 0.5% parts of benzoyl peroxide. 2.5 weight partsof the various coupling agent mixtures were added to 100 weight parts ofthe uncured resin/Novacite filler mixture. After thorough mixing anddevolatilization, the resulting mixtures were cast into 7 mm internaldiameter test tubes and allowed to cure overnight. Flexural strengths ofdry samples and of samples boiled in water for 24 bours were measured.The flexural strength of the castings was measured as the force requiredto break a sample with a 3 point loading over a 2 inch span. Severalcomposite rods were made with silane coupling agents withoutcrosslinkers, i.e. no disilyl compounds were used. The results of thesetests are reported in Table 3. Total silane compound composition foreach sample was 0.5 weight percent based on filler.

                  TABLE 3                                                         ______________________________________                                        Coupling Agents Flexural Strength of Castings (PSI)                           and Additive          Dry     24 Hr. Boil                                     ______________________________________                                        None                  12,800   9,800                                          Vinyltrimethoxysilane 15,400  11,900                                           A*                   18,800  14,700                                          B                     23,100  18,200                                           C*                   20,700  16,500                                          D                     21,100  18,100                                          E                     18,900  18,600                                          F                     20,000  18,600                                          G                     21,000  19,800                                          H                     17,800  17,300                                          I                     21,000  18,500                                           J*                   18,000  17,200                                           K*                   19,700  17,500                                          ______________________________________                                         Note: *denotes comparative example.                                      

Sample A was prepared with a solution of3-methacryloxypropyltrimethoxysilane. Sample B was prepared with amixture of 9 parts of the silane of Sample A and 1 part of the disilylcrosslinker hexamethoxy-1,2-disilylethane. Samples C-1 used the silanecoupling agent 3[2(vinylbenzylamino)ethylaminopropyltrimethoxysilane.Sample C used the coupling agent alone, whereas samples D-I used 9 partsof the coupling with 1 part of one of the disilyl crosslinker compoundsof Example 2. Sample D used disilyl crosslinker 1. Sample E used 2;Sample F used 3; Sample G used 4; Sample H used 5; and, Sample I used 7.Samples J and K used the known crosslinker compounds 9 and 10respectively from Example 2.

The results of the test show that all of the combinations of silanecoupling agent and disilyl crosslinker encompassed by the presentinvention (Samples B, and D through I showed increased dry and boiledflexural strengths relative to the samples without a coupling agent orcrosslinker. All of the invention samples showed better flexuralstrengths than composites made with vinyltrimethoxysilane.

The samples employing disilyl crosslinkers and silane coupling agentsshowed increased hydrolytic stability, i.e. after boiling the compositeswere stronger than samples which employed silanes alone.

EXAMPLE 4

This example illustrates the effectiveness of one embodiment of thepresent invention as a primer for epoxy resins to glass. 20 weightpercent solids, methanol solutions were made and used as primers forclean glass slides. Primer A employed the silane coupling agentN-(2-aminoethyl)-3-aminopropyltrimethoxysilane alone. Primer B employedthe same silane with hexamethoxy-1,2-disilylethane in a ratio of 9weight parts silane to 1 weight part disilyl compound. Primers C, D andE used the same constituents as Primer B, but the weight ratio of silaneto disilyl compound for each was 4 to 1, 1 to 1 and 1 to 9,respectively.

A two component epoxy mixture comprised of equal weights of DER-330™, acommercial bisphenyldiglycocidal ether resin sold by Dow Chemical,Midland, Mich., and Versamid (®), a polyamide amine curing agent sold byGeneral Mills, 140 was coated on the primed glass slide surfaces andcured for six days at room temperature. The adhesion of the epoxy to theslides was tested upon drying and after boiling the samples in water for2 hours. Samples which adhered so tenaciously to the glass slide thatthe epoxy could not be removed were rated excellent. Samples whichrequired significant efforts to remove the epoxy were rated good,samples which required little effort were rated fair, and samples wherethe epoxy did not adhere to the glass were rated poor. The results arereported in Table 4.

                  TABLE 4                                                         ______________________________________                                        Silane/Disilyl                                                                              Adhesion to Glass                                               Weight Ratio  Dry        After 2 Hour Boil                                    ______________________________________                                        No Primer     Good       Nil                                                  1/0           Excellent  Poor                                                 9/1           Excellent  Good                                                 4/1           Excellent  Fair                                                 1/1           Excellent  Poor                                                 1/9           Excellent  Excellent                                            ______________________________________                                    

The results show that the mixtures of the present invention when used asprimers adhere epoxy to glass better than silane coupling agent solutionprimers. The results also show that the best results are obtained whenthe silane coupling agent and the disilyl crosslinker are used inunequal weight ratios.

EXAMPLE 5

This example illustrates the effectiveness of the present invention as aprimer for epoxy resin based air dried paints on glass and cold rolledsteel surfaces. A commercially availabl epoxy floor paint was paintedand dried on primed surfaces, and the adhesion of the paint was testedafter air drying the samples for 3 days. The 90 peel strength of thedried paint film was measured upon drying, after 2 hours of waterimmersion, and after 1 day of water immersion. Primer A was a 50 weightpercent solids, methanol solution ofN-(2-aminoethyl)-3-aminopropyltrimethoxysilane and 5 weight percentwater. Primer B was a mixture of 10 weight parts of an epoxy resin soldas DER 667 by Dow Chemical Corp. (having a molecular weight of ˜2000),and 1 weight part N-(2-aminoethyl)-3-aminopropyltrimethoxysilane as a 5weight percent solids solution. Primer C was the same composition asPrimer B with the addition of 1 weight percenthexamethoxy-1,2-disilylethane. The results are reported in Table 5.

                  TABLE 5                                                         ______________________________________                                        Peel Strength of Epoxy to Primed Surfaces (lb./inch)                                 Glass                                                                         Wet            Cold Rolled Steel                                       Primer                                                                              Dry    2 Hr.  Wet 1 Day                                                                             Dry  Wet 2 Hr.                                                                             Wet 1 Day                            ______________________________________                                        None  0.3    Nil    Nil     0.6  Nil     Nil                                  A     c      1.1    Nil     c    1.8     3.0                                  B     c      c      4.4     c    c       3.0                                  C     c      c      c       c    c       c                                    ______________________________________                                    

In the Table, c denotes cohesive failure of the epoxy, indicating thatthe bond between the epoxy and the surface was stronger than the epoxycoat itself. The results demonstrate that addition of the disilylcrosslinker to primer composition B, to make primer composition C,improves the adhesion of the epoxy paint to both glass and cold rolledsteel surfaces, particularly in regards to the epoxy paint's resistanceto water immersion.

EXAMPLE 6

This example illustrates the handling properties of the compositions ofthe present invention on treated glass cloth. 0.5 weight percentsolutions of the following mixtures were made: a 9/1 weight mixture of3-methacryloxypropyltrimethoxysilane and hexamethoxy-1,2-disilylethanein water acidified with 0.1 weight percent acetic acid (A); and3-methacryloxy-propyltrimethoxysilane in water acidified with 0.1percent acetic acid (B). Heat cleaned glass cloth was treated with eachsolution and the treated cloths were measured for wet out time forvarious liquids, and judged for hand (how the treated cloth felt). Thecloth treated with a composition of the present invention, Solution A,was stiff, whereas treatment with the silane alone provided a softcloth. The wettability of the cloths is reported in Table 6.

                  TABLE 6                                                         ______________________________________                                        Wettability of Treated Heat Cleaned Glass Cloth                                           Wet-Out Time of 1 Drop of Liquid                                  Treatment                             Liquid                                  Solution Water    Mineral Oil                                                                              Liquid Epoxy                                                                           Polyester                               ______________________________________                                        A        1     min.   2 min.   4 min.   1   min.                              B        8     sec.   3 min.   9 min.   1   hour                              ______________________________________                                    

Although the cloth treated with a composition of the present inventionis stiffer than the cloth treated with the silane alone, and has alonger wet-out time for water, the cloth treated with the inventioncomposition had significantly better wet-out times for the organicliquids tested. Since composites made with glass cloth are typicallymade with epoxy or polyester resins, better wet-out times with thesepolymers should provide better quality composite products.

EXAMPLE 7

This example demonstrates the effectiveness of the coupling agentcompositions of the present invention to act as effective couplingagents in polyester fiberglass laminates. A 0.2 weight percent solids inwater solution of the following mixtures was made:3-methacryloxypropyltrimethoxysilane (A); 9 weight parts3-methacryloxypropyltrimethoxysilane and 1 weight parthexamethoxydisilylethane (B); 3 parts3-methacryloxypropyltrimethoxysilane and 1 part hexamethoxydisilylethane(C); and 1 part 3-methacryloxypropyltrimethoxysilane and 1 parthexamethoxydisilylethane (D). All of the solutions were adjusted to pH 4with acetic acid. Heat cleaned glass cloth, sold by Burlington Fibers as7781 Glass Cloth with 112 finish, was impregnated with the abovesolutions, air dried for 30 minutes, and oven dried at 110° C. for 7minutes. The cloth was then made into 14 ply laminates with polyesterresin. The resin used, a room temperature curing unsaturated polyesterresin, was ATLOC®400 ACI sold by ICI Americas with 1.25 weight percentmethylethylketone peroxide added to initiate the cure of the resin atroom temperature. The liquid polyester resin was applied to each layerof the laminate and allowed to fully wet the cloth. The 14 ply laminatewas placed in a press while curing to maintain a thickness of 0.125 inchin order to insure a glass content of the final laminate of about 65percent.

The flexural strength of each sample was tested dry, and after boilingin water for 24 hours and 72 hours according to accepted testprocedures. The results are reported in Table 7.

                  TABLE 7                                                         ______________________________________                                        Flexural Strength (PSI)                                                       Coupling Agent                                                                           Dry Flex  24 Hour Boil                                                                              72 Hour Boil                                 ______________________________________                                        None       63,000    --          22,000                                       A          76,000    60,000      --                                           B          73,000    61,000      --                                           C          76,000    57,000      --                                           D          70,000    42,000      37,000                                       ______________________________________                                    

The results show that the laminates made according to the presentinvention have approximately the same dry strength as the laminates madewith the silane coupling agent despite the fact that less silanecoupling agent is used.

What is claimed is:
 1. A .[.comprising.]. .Iadd.coupling agent andprimer .Iaddend..Iadd.mixture consisting essentially of: .Iaddend.(I) asilane coupling agent; .[.and.]. (II) a disilyl crosslinker compoundrepresented by the general formula

    (RO).sub.3 SiR'Si(OR).sub.3

wherein RO denotes an alkoxy radical having 1 to 8 carbon atoms, R' isselected from alkylene groups having 1 to 9 carbon atoms, ##STR5## inwhich x and y are 1 to 5.[...]. .Iadd., .Iaddend. ##STR6## in which xand y are between 0 and 3 inclusive, or ##STR7## in which s, t, u, and vare 1 to 3 inclusive and wherein the weight ratio of (I) : (II) isbetween 1:99 and 99:1 inclusive.Iadd.; and a solvent mutually compatiblewith said coupling agent (I) and said disilyl crossliner compound (II),whereby said mixture is effective as both a coupling agent and a primer..Iaddend.
 2. The composition of claim 1 wherein the R' radical of thedisilyl crosslinker compound is an alkylene radical with 1 to 8 carbonatoms.
 3. The composition of claim 2 wherein the R' radical of thedisilyl crosslinker compound is a methylene radical.
 4. The compositionof claim 2 wherein the R' radical of the disilyl crosslinker compound isan ethylene radical.
 5. The composition of claim 2 wherein the R'radical of the disilyl crosslinker compound is a propylene radical. 6.The composition of claim 2 wherein the R' radical of the disilylcrosslinker compound is a hexylene radical.
 7. The composition of claim1 wherein said divalent organic radical, R', of said disilyl crosslinkercompound is represented by the formula

    --(CH.sub.2).sub.x OOCCH═(CHCOO(CH.sub.2).sub.y --

where x and y have values of 1 to
 5. 8. The composition of claim 7wherein the R' radical of said disilyl crosslinker compound is.[.--(CH₂)₃ OOCCH═CHCOO(CH₂)₃ --.]. .Iadd.--(CH₂)₃ OOCCH═CHCOO(CH₂)₃ --..[.and wherein the composition further comprises a solvent mutuallycompatible with said coupling agent (I) and said disilyl crosslinkercompound (II)..].
 9. The composition of claim 1 wherein the divalentorganic radical of said disilyl crosslinker compound is of the generalformula ##STR8## where the value of x and y is between 0 and 3inclusive, the two alkylene radicals are positioned either meta or paraon the benzene ring, .[.and wherein the composition further comprises asolvent mutually compatible with said coupling agent (I) and saiddisilyl crosslinker compound (II).]..
 10. The composition of claim 9wherein the value of x and y is zero.
 11. The composition of claim 1wherein the R' radical of the disilyl crosslinker compound isrepresented by the general formula ##STR9## where s, t, u, and v havevalues between 1 and 3 inclusive.Iadd..[., and and wherein thecomposition further comprises a solvent mutually compatible with saidcoupling agent (I) and said disilyl crosslinker compound(II).]..Iaddend..
 12. The composition of claim 2 wherein the silanecoupling agent is an aminofunctional silane coupling agent chosen fromthe group consisting ofN-(2-aminoethyl)-3-aminopropyltrimethoxysilane,(aminoethylaminomethyl)phenyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltris(2-ethylhexoxy) silane, 3-aminopropyltrimethoxysilane,trimethoxysilylpropyldiethylenetriamine, 3-aminopropyltrimethoxysilane,aminopropyltriethoxysilane,bis(2-hydroxyethyl)-3-aminopropyltrimethoxysilane, and4-aminobutyltriethoxysilane.
 13. The composition of claim 12 wherein thesilane coupling agent isN-(2-aminoethyl)-3-aminopropyltrimethoxysilane.[., and the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 14. The composition of claim 2 wherein the silanecoupling agent is a methacrylic functional couplingagent chosen from thegroup consisting of 3-methacryloxypropyltrimethoxysilane, and2-methacryloxyethyldimethyl[3-trimethoxysilylpropyl]ammonium chloride.15. The composition of claim 14 wherein the silane coupling agent is3-methacryloxypropyl-trimethoxysilane.[., and the composition furthercomprises a mutual solvent for said disilyl crosslinker and couplingagent.]..
 16. The composition of claim 2 wherein the silane couplingagent is a epoxy functional coupling agent chosen from the groupconsisting of 3-glycidoxypropyltrimethoxysilane, and beta (3,4epoxycyclohexyl) ethyltrimethoxysilane.[., and where the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 17. The composition of claim 2 wherein the silanecoupling agent is a vinyl functional coupling agent chosen from thegroup consisting of 3[2(vinyl benzylamino)ethylamino]propyltrimethoxysilane, triacetoxyvinylsilane,tris-(2-methoxyethoxy)vinylsilane, vinyltrimethoxysilane, and vinyltris(t-butylperoxy)silane.[., and where the composition furthercomprises a mutual solvent for said disilyl crosslinker and couplingagent.]..
 18. The composition of claim 2 wherein the silane couplingagent is a halo-organic radical functional coupling agent chosen fromthe group consisting of 3-chloropropyltrimethoxysilane, and3-chloropropyltriethoxysilane,1-trimethoxysilyl-2-(p,m-chloromethyl)phenyl-ethane, and where thecomposition further comprises a mutual solvent for said disilylcrosslinker and coupling agent.
 19. The composition of claim 18 wherethe haloorganic radical is 3-chloropropyltrimethoxysilane.
 20. Thecomposition of claim 2 wherein the silane coupling agent is a mercaptofunctional coupling agent chosen from the group consisting ofmercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane,3-mercaptopropylmethyltrimethoxysilane, and3-mercaptopropylmethyidimethoxysilane.[., and where the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 21. The composition of claim 3 wherein the silanecoupling agent is an aminofunctional silane coupling agent chosen fromthe group consisting ofN-(2-aminoethyl)-3-aminopropyltrimethoxysilane,(aminoethylaminomethyl)phenyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltris(2-ethylhexoxy) silane, 3-aminopropyltrimethoxysilane,trimethoxysilylpropyldiethylenetriamine, 3-aminopropyltrimethoxysilane,aminopropyltriethoxysilane,Bis(2-hydroxyethyl)-3-aminopropyltrimethoxysilane, and4-aminobutyltriethoxysilane.
 22. The composition of claim 21 wherein thesilane coupling agent isN-(2-aminoethyl)-3-aminopropyltrimethoxysilane.[., and the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 23. The composition of claim 3 wherein the silanecoupling agent is a methacrylic functional coupling agent chosen fromthe group consisting of 3-methacryloxypropyltrimethoxysilane, and2-methacryloxyethyldimethyl[3-trimethoxysilylpropyl]ammonium chloride.24. The composition of claim 23 wherein the silane coupling agent is3-methacryloxypropyl-trimethoxysilane.[., and the composition furthercomprises a mutual solvent for said disilyl crosslinker and couplingagent.]..
 25. The composition of claim 3 wherein the silane couplingagent is a epoxy functional coupling agent chosen from the groupconsisting of 3-glycidoxypropyltrimethoxysilane, and beta (3,4epoxycyclohexyl) ethyltrimethoxysilane.Iadd..[., and where thecomposition further comprises a mutual solvent for said disilylcrosslinker and coupling agent.]..Iaddend..
 26. The composition of claim3 wherein the silane coupling agent is a vinyl functional coupling agentchosen from the group consisting of 3[2(vinyl benzylamino)ethylamino]propyltrimethoxysilane, triacetoxyvinylsilane,tris-(2-methoxyethoxy)vinylsilane, vinyltrimethoxysilane, and vinyltris(t-butylperoxy)silane.[., and where the composition furthercomprises a mutual solvent for said disilyl crosslinker and couplingagent.]..
 27. The composition of claim 3 wherein the silane couplingagent is a halo-organic radical functional coupling agent chosen fromthe group consisting of 3-chloropropyltrimethoxysilane, and3-chloropropyltriethoxysilane,1-trimethoxysilyl-2-(p,m-chloromethyl)phenyl-ethane.
 28. The compositionof claim 27 where the haloorganic radical is3-chloropropyltrimethoxysilane.[., and the composition further comprisesa mutual solvent for said disilyl crosslinker and coupling agent.].. 29.The composition of claim 3 wherein the silane coupling agent is amercapto functional coupling agent chosen from the group consisting ofmercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane,3-mercaptopropylmethyltrimethoxysilane, and3-mercaptopropylmethyldimethoxysilane.[., and where the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 30. The composition of claim 4 wherein the silanecoupling agent is an aminofunctional silane coupling agent chosen fromthe group consisting ofN-(2-aminoethyl)-3-aminopropyltrimethoxysilane,(aminoethylaminomethyl)phenyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltris(2-ethylhexoxy) silane, 3-aminopropyltrimethoxysilane,trimethoxysilylpropyldiethylenetriamine, 3-aminopropyltrimethoxysilane,aminopropyltriethoxysilane,Bis(2-hydroxyethyl)-3-aminopropyltrimethoxysilane, and4-aminobutyltriethoxysilane.
 31. The composition of claim 30 wherein thesilane coupling agent isN-(2-aminoethyl)-3-aminopropyltrimethoxysilane.[., and the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 32. The composition of claim 4 wherein the silanecoupling agent is a methacrylic functional coupling agent chosen fromthe group consisting of 3-methacryloxypropyltrimethoxysilane, and2-methacryloxyethyldimethyl[3-trimethoxysilylpropyl]ammonium chloride.33. The composition of claim 32 wherein the silane coupling agent is3-methacryloxypropyl-trimethoxysilane.[., and the composition furthercomprises a mutual solvent for said disilyl crosslinker and couplingagent.]..
 34. The composition of claim 4 wherein the silane couplingagent is a epoxy functional coupling agent chosen from the groupconsisting of 3-glycidoxypropyltrimethoxysilane, and beta (3,4epoxycyclohexyl) ethyltrimethoxysilane.[., and where the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 35. The composition of claim 4 wherein the silanecoupling agent is a vinyl functional coupling agent chosen from thegroup consisting of 3[2(vinyl benzylamino)ethylamino]propyltrimethoxysilane, triacetoxyvinylsilane,tris-(2-methoxyethoxy)vinylsilane, vinyltrimethoxysilane, and vinyltris(t-butylperoxy)silane.[., and where the composition furthercomprises a mutual solvent for said disilyl crosslinker and couplingagent.]..
 36. The composition of claim 4 wherein the silane couplingagent is a halo-organic radical functional coupling agent chosen fromthe group consisting of 3-chloropropyltrimethoxysilane,3-chloropropyltriethoxysilane,1-trimethoxysilyl-2-(p,m-chloromethyl)pbenylethane.
 37. The compositionof claim 36 where the haloorganic radical is3-chloropropyltrimethoxysilane.[., and the composition further comprisesa mutual solvent for said disilyl crosslinker and coupling agent.].. 38.The composition of claim 4 wherein the silane coupling agent is amercapto functional coupling agent chosen from the group consisting of3-mercaptopropylmethyltrimethoxysilane, and3-mercaptopropylmethyldimethoxysilane.[., and where the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 39. The composition of claim 10 wherein the silanecoupling agent is an aminofunctional silane coupling agent chosen fromthe group consisting ofN-(2-aminoethyl)-3-aminopropyltrimethoxysilane,(aminoethylaminomethyl)phenyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltris(2-ethylhexoxy) silane, 3-aminopropyltrimethoxysilane,trimethoxysilylpropyldiethylenetriamine, 3-aminopropyltrimethoxysilane,aminopropyltriethoxysilane,Bis(2-hydroxyethyl)-3-aminopropyltrimethoxysilane, and4-aminobutyltriethoxysilane.
 40. The composition of claim 39 wherein thesilane coupling agent isN-(2-aminoethyl)-3-aminopropyltrimethoxysilane.[., and the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 41. The composition of claim 10 wherein the silanecoupling agent is a methacrylic functional coupling agent chosen fromthe group consisting of 3-methacryloxypropyltrimethoxysilane, and2-methacryloxyethyldimethyl[3-tri-methoxysilylpropyl]ammonium chloride.42. The composition of claim 41 wherein the silane coupling agent is3-methacryloxypropyl-trimethoxysilane.[., and the composition furthercomprises a mutual solvent for said disilyl crosslinker and couplingagent.]..
 43. The composition of claim 10 wherein the silane couplingagent is an epoxy functional coupling agent chosen from the groupconsisting of 3-glycidoxypropyltrimethoxysilane, and beta (3,4epoxycyclohexyl) ethyltrimethoxysilane.[., and where the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 44. The composition of claim 10 wherein the silanecoupling agent is a vinyl functional coupling agent chosen from thegroup consisting of 3[2(vinyl benzylamino)ethylamino]propy]trimethoxysilane, triacetoxyvinylsilane, and vinyltris-(2-methoxyethoxy)vinylsilane, vinyltrimethoxysilane, and vinyltris(t-butylperoxy)silane.[., and where the composition furthercomprises a mutual solvent for said disilyl crosslinker and couplingagent.]..
 45. The composition of claim 10 wherein the silane couplingagent is a halo-organic radical functional coupling agent chosen fromthe group consisting of 3-chloropropyltrimethoxysilane, and3-chloropropyltriethoxysilane,1-trimethoxysilyl-2-(p,m-chloromethyl)phenyl-ethane.[., and where thecomposition further comprises a mutual solvent for said disilylcrosslinker and coupling agent.]..
 46. The composition of claim 45 wherethe haloorganic radical is 3-chloropropyltrimethoxysilane.[., and thecomposition further comprises a mutual solvent for said disilylcrosslinker and coupling agent.]..
 47. The composition of claim 10wherein the silane coupling agent is a mercapto functional couplingagent chosen from the group consisting ofmercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane,3-mercaptopropylmethyltrimethoxysilane, and3-mercaptopropylmethyldimethoxysilane.[., and where the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 48. The composition of claim 8 wherein the silanecoupling agent is an amino functional silane coupling agent chosen fromthe group consisting ofN-(2-aminoethyl)-3-aminopropyltrimethoxysilane,(aminoethylaminomethyl)phenyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltris(2-ethylhexoxy) silane, 3-aminopropyltrimethoxysilane,trimethoxysilylpropyldiethylenetriamine, 3-aminopropyltrimethoxysilane,aminopropyltriethoxysilane,Bis(2-hydroxyethyl)-3-aminopropyltrimethoxysilane, and4-aminobutyltriethoxysilane.
 49. The composition of claim 48 wherein thesilane coupling agent isN-(2-aminoethyl)-3-aminopropyltrimethoxysilane.[., and the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 50. The composition of claim 8 wherein the silanecoupling agent is a methacrylic functional coupling agent chosen fromthe group consisting of 3-methacryloxypropyltrimethoxysilane, and2-methacryloxyethyldimethyl[3-trimethoxysilylpropyl]ammonium chloride.51. The composition of claim 50 wherein the silane coupling agent is3-methacryloxypropyl-trimethoxysilane.[., and the composition furthercomprises a mutual solvent for said disilyl crosslinker and couplingagent.]..
 52. The composition of claim 8 wherein the silane couplingagent is a epoxy functional coupling agent chosen from the groupconsisting of 3-glycidoxypropyltrimethoxysilane, and beta (3,4epoxycyclohexyl) ethyltrimethoxysilane.[., and where the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..
 53. The composition of claim 8 wherein the silanecoupling agent is a vinyl functional coupling agent chosen from thegroup consisting of 3[2(vinyl benzylamino)ethylamino]propyltrimethoxysilane, triacetoxyvinyisilane, tris-(2-methoxyethoxy)vinylsilane, vinyltrimethoxysilane, and vinyltris(t-butylperoxy)silane.[., and where the composition furthercomprises a mutual solvent for said disilyl crosslinker and couplingagent.]..
 54. The composition of claim 8 wherein the silane couplingagent is a halo-organic radical functional coupling agent chosen fromthe group consisting of 3-chloropropyltrimethoxysilane, and3-chloropropyltriethoxysilane,1-trimethoxysilyl-2-(p,m-chloromethyl)phenyl-ethane.[., and where thecomposition further comprises a mutual solvent for said disilylcrosslinker and coupling agent.]..
 55. The composition of claim 54 wherethe haloorganic radical is 3-chloropropyltrimethoxysilane.
 56. Thecomposition of claim 8 wherein the silane coupling agent is a mercaptofunctional coupling agent chosen from the group consisting ofmercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane,3-mercaptopropylmethyltrimethoxysilane, and3-mercaptopropylmethyldimethoxysilane.[., and where the compositionfurther comprises a mutual solvent for said disilyl crosslinker andcoupling agent.]..